I have both the 9compact and the 9 full size M&P's. The compact came first and has been a flawless performer.
The full size 9 came 6 months ago and the differences between the triggers is night and day. The compact's trigger while long and with a less than positive reset was from the beginning without the grittiness I've heard so much about and breaks at just below 5lbs. The full size trigger was exactly as reported by others, gritty, gritty, gritty, and is currenty being upgraded to the apex system.
I enjoy both and have decided I prefer them to my G19.
What exactly did you not like about your full size M&P, I'm not sure I'm following you? Just curious